In various data and computer systems, data may be exchanged between modules by way of a serial data interface. This is illustrated at a high level in FIG. 1, where modules 104 and 106 exchange data over transmission lines 102. Modules 104 and 106 include transmit and receive functional units 108 and 110, respectively. Module 104 or module 106 may be, for example, a discrete chip (die), a board, or a higher level component in a system. For purposes of testing a serial interface, module 104, module 106, or both, may be special-purpose test equipment, such as, for example, a serial bus analyzer, sometimes referred to as a real-time scope.
Jitter may be defined as the short-term variation of a signal with respect to its ideal position in time. For some current specifications of high speed serial data interfaces, it is useful to characterize the jitter present in a data signal by decomposing the total jitter into a deterministic component and a random component. For example, the bit error rate (BER) is usually difficult to measure directly because it is a very small number, for example, on the order of e−12. However, the BER of a data communication system may be estimated based upon the deterministic and random components of total jitter. It is therefore useful to provide a method for decomposing measured total jitter into its deterministic and random components.